In Hindsight, Bruce should of had the same resolve as many other superheroes[Like spider-man,Kyle Rayner etc] after his "true love" was killed, and kept on fighting no matter what. But after the dark knight, he gave up.

He showed that resolve in TDK, when he quickly got back on the saddle and stopped The Joker. He only quit on being Batman once he was no longer needed in Gotham. But ultimately he was just waiting for things to go bad again so he'd have a purpose.